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United States Patent |
5,706,903
|
Odendahl
,   et al.
|
January 13, 1998
|
Tool
Abstract
A device on machine tools for transmitting a rotational and/or percussive
movement to a tool (22) has two or three rotational drivers (14) which are
arranged so as to be symmetrical with respect to rotation. The rotational
drivers (14) are stepped and flank parts (16) extending radially to the
center axis (15) alternate with guide portions (17) extending along a
cylindrical outer surface. Locking members (20) which engage in
depressions (28) at the tool (22) are arranged in the region of the
rotational drivers (14) for the axial locking of the tools (10). With the
tool holder (10) according to the invention, tool shafts having diameters
between 8 and 12 mm can be clamped without converting or modifying the
tool shafts. Good true running characteristics can be achieved in spite of
the stationary rotational drivers (14).
Inventors:
|
Odendahl; Alfred (Waldenbuch, DE);
Wanner; Karl (Leinfelden-Echterdingen, DE)
|
Assignee:
|
Robert Bosch GmbH (Stuttgart, DE)
|
Appl. No.:
|
419507 |
Filed:
|
April 10, 1995 |
Foreign Application Priority Data
| Sep 26, 1991[DE] | 41 32 023.9 |
Current U.S. Class: |
173/104; 279/19.3 |
Intern'l Class: |
B23B 031/02; B25D 017/08 |
Field of Search: |
173/104
279/19.3,19.5
408/226
|
References Cited
U.S. Patent Documents
3916435 | Oct., 1975 | Camplin.
| |
4107949 | Aug., 1978 | Wanner et al. | 408/226.
|
4123074 | Oct., 1978 | Wanner | 279/19.
|
4131165 | Dec., 1978 | Wanner et al. | 279/19.
|
4206820 | Jun., 1980 | Bailey et al. | 279/19.
|
4691929 | Sep., 1987 | Neumaier et al. | 279/19.
|
5340245 | Aug., 1994 | Bloechle et al. | 279/19.
|
5346340 | Sep., 1994 | Runge | 408/226.
|
Foreign Patent Documents |
0141990 | Sep., 1984 | EP.
| |
906434 | Sep., 1962 | GB.
| |
91 20119 | Dec., 1991 | WO.
| |
Other References
Patent Abstracts of Japan vol. 16, No. 227 (E-1207) May 26, 1992.
|
Primary Examiner: Smith; Scott A.
Attorney, Agent or Firm: Striker; Michael J.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation application of Ser. No. 211,328 filed on
Mar. 25, 1994, now U.S. Pat. No. 5,474,139.
Claims
What is claimed is:
1. A tool for at least one of a drill chuck and a tool holder having a
plurality of inwardly projecting rotational drivers with flanks extending
approximately radially and connected by guide portions, for a hand-held
drill or hammer device, the tool comprising a shaft provided with a
plurality of grooves which are arranged to receive the drivers and located
at angular intervals at a circumference of said shaft, said grooves having
at least on one side a plurality of substantially planar lateral walls
which are arranged approximately radially to a tool axis in a stepped
manner and are connected with one another by connecting portions.
2. A tool as defined in claim 1, wherein said connecting portions extend
along a cylindrical outer surface.
3. A tool as defined in claim 1, wherein said grooves are spaced from one
another by equal angular intervals.
4. A tool as defined in claim 1, wherein said shaft has depressions which
form axial extensions of said grooves.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a tool for at least one of a drill chuck
and a tool holder having a plurality of inwardly projecting rotational
drivers. A tool holder which is constructed as a drill chuck and Whose
rotational driving elements are formed by a plurality of gripping segments
lying one on top of another is known from DE-U 85 10 262. The gripping
segments have an approximately trapezoidal or circular cross-sectional
shape, are curved in profile, and merge with one another in curved
portions. The lateral surfaces of the rotational drivers are accordingly
not planar and are arranged relative to the direction of the application
of force in a disadvantageous manner for the transmission of torque.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a tool for
at least one of a drill chuck and a tool holder, which avoids the
disadvantages of the prior art.
In keeping with these objects and with others which will become apparent
hereinafter, the tool has a shaft having an insertion end and provided
with a plurality of grooves which are open toward said insertion end and
arranged at angular intervals over at a circumference of said shaft, said
grooves having planar lateral walls which are arranged approximately
radially to a tool axis and connected by radial portions in the shape of a
cylindrical outer surface.
When the tool is designed in accordance with the present invention it has
the special advantage that a standardized shaft is not required. Rather,
thinner and thicker tool shafts can be inserted into the same tool
receptacle depending on the diameter of the tool head. This is achieved by
means of stepped rotational driving slots or grooves. The greater the
difference in diameter between tools, the more steps must be provided.
The novel features which are considered as characteristic for the invention
are set forth in particular in the appended claims. The invention itself,
however, both as to its construction and its method of operation, together
with additional objects and advantages thereof, will be best understood
from the following description of specific embodiments when read in
connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a device on hand-held machine tools in cross section with an
inserted tool shaft of small diameter;
FIGS. 2 and 3 show the same device with inserted tools of different sizes;
FIG. 4 shows a device with two rotational drivers in another embodiment
example;
FIG. 5 shows a longitudinal section through a tool holder according to FIG.
2.
DESCRIPTION OF THE EMBODIMENT EXAMPLES
The device according to the invention substantially has a tool holder 10
and a tool 22 held therein. A base body 11 of the tool holder 10 with a
receptacle hole 12 is shown in section. In the first embodiment example,
three identically constructed, stationary rotational drivers 14 project
into the receptacle hole 12. The rotational drivers 14 have a stepped
construction, and planar flank parts 16 extending radially with reference
to the center axis 15 of the tool holder 10 alternate with guide portions
17 constructed with a cylinder-shaped outer surface in the circumferential
direction. The receptacle hole 12 itself also acts as a guide portion. The
rotational drivers 14 are stepped in such a way that the guide portions 17
are situated on a cylindrical outer surface having a diameter of 6 mm, 8
mm and 10 mm coaxially to the center axis 15. The receptacle hole 12 has a
diameter of 12 mm.
The rotational drivers 14 extend a certain distance along the receptacle
hole 12. Roughly in the center of this distance, the rotational drivers 14
are penetrated by an opening 19 which also penetrates the base body 11.
Locking members 20 are inserted into the openings 19 and project somewhat
beyond the projected area of the rotational drivers 14. The locking
members 20 are advantageously constructed as balls, rollers or stepped
locking bodies according to DE 35 06 008 A1 (=GB 21 71 340), whose
contents are incorporated in this application.
A tool 22 is clamped in the tool holder 10. The tool 22 has grooves 23
which open out toward its shaft end and extend along the shaft for
rotational driving. In the tool shown in FIG. 1, the latter are simple
grooves without steps and with planar lateral walls 25 arranged radially
to the tool axis 24 and a roughly planar base surface 26 connecting the
lateral walls 25. In the region of the locking members 20, the tool 22 has
three depressions 28 forming an extension of the grooves 23. The
depressions 28 are advantageously elongated in the axial direction of the
tool 22 and are longer than the locking members 20 by an amount
corresponding to the idle path of the tool.
The tool holder 10 has a sliding sleeve 29 which surrounds the base body 11
and the locking members 20 and is longitudinally displaceable within
limits (see also FIG. 5). It contains a thickened portion or a retaining
ring 30 which secures the locking members 20 in the depressions 28. A
plate ring 31 having elongations 32 in the region of the locking members
20 contacts the retaining ring 30 laterally. The plate ring 31 is pressed
against the sliding sleeve 29 and the retaining ring 30 by a pressure
spring 33.
As is shown in FIG. 5 in dashed lines, the locking members 20 are deflected
radially against the force of the pressure spring 33 when a tool is
inserted into the receptacle hole 17. When the tool shaft is fully
inserted, the locking members 20 are forced back again by the pressure
spring 33 into their initial positions so as to lock. In other respects,
the design and operation correspond to the description in DE 32 05 063 C2
(GB 20 96 045 B2) whose contents are incorporated herein by reference.
The retaining ring 30 and plate ring 31 can be adapted to the locking
members 20 in such a way that the position of the plate ring 31 indicates
the penetration depth of the locking members 20 and accordingly the shaft
diameter of the inserted tool. The position of the plate ring 31 or the
position of a corresponding sleeve can then be referred to for the purpose
of adjusting the speed of the drive motor. In this case, in contrast to
the FIGS. 1 to 4, the depressions 28 would have to be constructed with
different depths depending on the diameter of the shaft.
The tool holder 10 shown in FIG. 2 is identical to that shown in FIG. 1,
with the exception that a tool shaft 30 with a large diameter is now
inserted. The tool 30 likewise has longitudinally extending grooves 33
which are formed by two pairs of lateral walls 35 which are offset in the
circumferential direction. The grooves 33 are thus stepped and radial
portions 37 are formed between the lateral walls 35. The radial portions
37 are adapted to the guide portions 17 of the tool holder 10 and extend
along a cylindrical outer surface.
In FIG. 3, a third tool 40 is shown in the tool holder 10 which is
identical to that shown in the previous figure. The shaft of the tool 40
has a diameter of 12 mm and contacts the receptacle hole 12. The grooves
43 have three steps instead of two steps as in the preceding figure. Three
pairs of lateral walls 45 alternate with radial portions 47. In other
respects, the tool 40 corresponds to the tools 22 and 30 shown above.
The second embodiment example according to FIG. 4 is distinguished from the
first embodiment example only in that two rotational drivers 14 are
constructed at the tool receptacle 10' and only two grooves 33 are
constructed at the tool 50. It has the particular advantage that tools
with two or four grooves at the shaft can also be clamped.
To insert a tool 22 into the tool holder 10, the rotational drivers 14 are
aligned with the grooves 23 and the tool 22 is slid into the receptacle
hole 12. When the end of the tool shaft reaches the locking members 20,
the latter are deflected outward, preferably radially, and catch in the
depressions 28 again as the tool is slid forward. The tool 23 may not
readily be pulled out, since the locking members 20 are prevented, e.g. by
a sleeve, from deflecting in this direction. To remove a tool, this sleeve
must first be actuated by the user. The tool 22 is centered and guided by
the guide portions 17 at the rotational drivers 14. This results in good
true running or concentric running characteristics in spite of the
stationary rotational drivers 14. To facilitate insertion of a tool, the
rotational drivers can either be beveled at their front edge or the
grooves 23 can be beveled at the end of the shaft. In the tool with a
shaft of 10 mm, according to FIGS. 2 and 4, the centering and guidance is
improved by additional guide portions 17.
Because of the stepped construction of the rotational drivers 14, the
device, according to the invention, for transmitting a rotating and/or
percussive movement to a tool is suitable for various shaft diameters
without requiring any modification of the tool holder 10. Drilling tools
with drill diameters between 4 mm and 8 mm receive a shaft diameter of 8
mm and are inserted into the tool holder 10 according to FIG. 1. Tools
with drill diameters between 8 mm and 12 mm receive a 10-mm shaft
according to FIG. 2. Tools with drill diameters greater than 12 mm are
outfitted with a shaft diameter of 12 mm and fit into the tool holder 10
according to the invention with reference to FIG. 3.
The device according to the invention can also be used for mechanically
sensing the size of the inserted tool. The depth of the depressions 28 are
constructed differently with reference to the receptacle hole 17 depending
on the drill head diameter. Consequently, the locking members 20 engage at
different depths. The end position of the locking members 20 determines
the position of a sensing sleeve within the tool receptacle as is
described in DE 35 06 008 A1 (GB 21 71 340 B) whose disclosure is
incorporated herein by reference. Depending on the position of the sensing
sleeve, the speed of the drill is correctly adjusted corresponding to the
drill diameter.
It will be understood that each of the elements described above, or two or
more together, may also find a useful application in other types of
constructions differing from the types described above.
While the invention has been illustrated and described as embodied in a
tool for at least one of a drill chuck and a tool holder, it is not
intended to be limited to the details shown, since various modifications
and structural changes may be made without departing in any way from the
spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of
the present invention that others can, by applying current knowledge,
readily adapt it for various application without omitting features that,
from the standpoint of prior art, fairly constitute essential
characteristics of the generic or specific aspects of this invention.
What is claimed as new and desired to be protected by the Letters Patent is
set forth in the appended claims.
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